In recent years, radiographic imaging apparatuses including a flat panel detector (hereinafter abbreviated as FPD) formed of a semiconductor material have begun to be put into practice as radiographic apparatuses used for X-ray medical diagnostic imaging or non-destructive inspection. Such radiographic imaging apparatuses are used as, for example, in medical diagnostic imaging, digital imaging apparatuses for use in still image radiography such as general radiography or moving image radiography such as fluoroscopic radiography.
In fluoroscopic radiography using a digital imaging apparatus, a method and apparatus disclosed in PTL 1 for processing a fluoroscopic image are available. In the method and apparatus disclosed in PTL 1, a lag (afterimage) prediction model is generated by generating at least two dark images after scanning an object being examined, the object being examined is scanned, and the lag prediction model is periodically updated during the scan.
Further, the capabilities of the above radiographic imaging apparatuses to switch between an area (field-of-view size) that is read by an FPD and a radiation area of X-rays have been studied. However, in a case where switching is performed so as to increase the radiation area, the sensitivity or dark output of pixels differs between the irradiated area and the non-irradiated area of the FPD. Thus, an obtained image may contain a ghost (image step) that is affected by the radiation area, leading to reduced quality of the image. In PTL 2, an examination is made of performing image processing to correct for such a ghost or the like that is affected by the radiation area. Specifically, ghost correction coefficients are obtained for each X-ray irradiation condition on the basis of data that includes a ghost and that is obtained by uniform irradiation. From the obtained ghost correction coefficients, a required ghost correction coefficient corresponding to X-ray irradiation conditions for collecting data regarding the part being examined, which is the radiation area, and corresponding to the time taken from the start of X-ray irradiation is obtained. Thus, the data regarding the part being examined is corrected using the required ghost correction coefficient, and corrected image data is generated.